If the European Union is to become anything more than a glorified free trade zone or a terribly ineffective confederation, it needs to get closer and move forward with those members who are willing to diminish their own sovereign powers in the pursuit of a more perfect and secure union. That won’t happen with the U.K. on board.

So far, much of the discussion concerning a Brexit has focused on what leaving the E.U. would mean for Britain and its interests. Would it hurt the City of London’s status as the financial heart of Europe? Would it diminish Britain’s role on the world stage? But hardly anyone in the U.K., or elsewhere for that matter, is asking the bigger question: Would Brexit be good for the E.U.? The answer is a resounding “yes.”

It is difficult to build a strong team when one of the members believes it can pick and choose what it wants to do all the time. While the U.K. may be a full-fledged member of the E.U., it has chosen to “opt-out” of a multitude of provisions that it felt could compromise its sovereignty or threaten the profits of the big financial firms in the City of London.

This isn’t a recent phenomenon. Back in 1978, the U.K. was the only member of the European Economic Community (EEC), the direct predecessor to the European Union, not to join the European Monetary System (EMS). That pretty much doomed the experiment from the outset. And while the U.K. joined the European Exchange Rate Mechanism in 1990, it was kicked out two years later after the devaluation of its currency against its European rivals. Then in 2002, the U.K. failed to join 12 other member states in adopting the euro, choosing instead to keep the pound.

In 2011, U.K. Prime Minister David Cameron vetoed legislation that would have brought eurozone nations closer together in a fiscal compact because the City of London was against the introduction of a financial transaction tax or anything that might lead to a unified European banking system. Eurozone members in favor of the tax later banded together to adopt the measure without the U.K.’s say. They have also moved forward with creating a banking union and harmonizing a number of rules dealing with bank liquidity. In all of this, the U.K. is nowhere to be found.

Britain’s lack of commitment to the European Union goes beyond financial matters. The U.K. was one of only two nations in the E.U. to “opt-out” of the E.U. Charter of Fundamental Rights on the erroneous claim that it would somehow spell disaster for businesses in Britain. Then in 1995, Britain refused to sign the Schengen Agreement, which allowed member states to eliminate internal border controls, helping to increase trade and efficiency on the continent. Schengen advanced the notion of a common European polity, as people could go back and forth between countries as easily as Americans can travel between states. Britain’s failure to adopt Schengen was a reminder of the island nation’s lack of trust in its European allies and it put further distance between it and the rest of “the continent.”

To be sure, sovereign nations have a duty to put national interests above those of other nations, but when the U.K. signed the Treaty of Maastricht in the early 1990s and the Treaty of Lisbon in 2007, it understood that the EEC, the direct predecessor to the European Union, was morphing into a political body and would no longer be a purely economic organization. The structures put in place were clearly intended to lead to a closer political and fiscal union, which required member states to give up some of their sovereignty. If the U.K. was not comfortable taking that step, it should have not moved forward in the first place. Its continued obstructionism and “me first” attitude in all areas, especially in finance, have undermined the efforts of European countries fighting for a closer and more secure Europe.

When London’s mayor, Boris Johnson, told reporters on Sunday that he would support Brexit, the U.K. government issued a statement that pretty much sums up Britain’s lack of commitment to the E.U. and its opportunistic agenda: “Our message to everyone is we want Britain to have the best of both worlds: all the advantages of the jobs and investment that come with being in the EU, without the downsides of being in the euro and open borders.”

The U.K. is not the only one that wants to have its cake and eat it too. Denmark and Sweden have also wavered in their commitment to greater integration. So, the U.K. shouldn’t be the only one to leave the E.U. quickly; all other member states fundamentally opposed to building a stronger E.U. would be wise to head for the exits as well. The policy of “opting out” of E.U. provisions by any member state should be erased as it only creates divisions and confusion inside and outside of Europe. By attempting to accommodate all members, the E.U. has become weak and ineffective, unable to respond to even basic crises.

The opt-out disease is spreading, with member states taking it upon themselves to close borders and restrict trade and commerce due to the E.U.’s broken immigration policy. Imagine if the governor of Texas sealed the U.S. border with Mexico. Would the federal government just throw up its hands and say “whatever”? No, because the border police is controlled by Washington, not by the states. This is why the E.U. needs to go beyond just having a common immigration policy on paper; it needs enforcement mechanisms to ensure the policy is administered fairly and equally across member states.

Keeping Britain in the E.U. will only make it more difficult for other member states to implement the necessary reforms to fix the organization’s structural problems. But something big has to happen to give member states the courage to kill off the ineffective, please-everyone European Union. It didn’t happen when member states failed to unanimously support the E.U. constitution in 2004. It also didn’t happen after the near-collapse of the euro currency in 2011, or the overreach by the European Central Bank in 2014, or even the various Greek financial scares of 2011, 2012, 2013, 2014, and 2015.

But the Syrian migrant crisis, an increasingly aggressive Russia, the possible onset of an isolationist United States, mixed in with something as existentially damaging as Brexit might just be the proper toxic brew needed to euthanize the current structure and begin anew. To be sure, Brexit, along with the removal of the other obstructionist and noncommittal member states, won’t be enough to bring about positive change—but it is a necessary step just the same. After the U.K. and the other obstructionists are removed, it will be up to the original founding members, Germany and France, to get the E.U. back on track.